This invention relates to impact printers and, more particularly, to impact printers where a ribbon moves between a ribbon storage area and a print point to continuously supply fresh ribbon to a position between a character element and a print receiving medium.
Copending applications Ser. Nos. 833,257, filed Sept. 14, 1977 and abandoned in favor of copending application Ser. No. 98,773, filed Nov. 30, 1979, Ser. No. 833,270, filed Sept. 14, 1977, Ser. No. 833,269, filed Sept. 14, 1977, now abandoned and Ser. No. 873,714, filed Jan. 30, 1978, now abandoned disclose ribbon cartridges for impact printers which include flexible leaders or guides which guide the ribbon from the stationary storage area within the cartridge housing to a movable print point. By utilizing the flexible leaders so as to permit the storage area to remain stationary, it is possible to store much larger amounts of ribbon within the cartridge without affecting performance of the printer since the carriage for the printing mechanism need not move the stored ribbon, but merely that portion of the ribbon which is guided to the print point by the flexible leaders. Since a large amount of ribbon may be stored within the cartridge, the operator of the printer is not required to change the cartridge as often and thus avoids the risk of defacing the print receiving medium during replacement of the cartridge, e.g., smearing may be avoided. In addition, the use of a cartridge capable of substantial ribbon storage is more cost-efficient when one considers that the cartridge is, in effect, disposable. In other words, where the capacity for ribbon storage is quite large, the ratio of the cartridge mechanism cost to the ribbon is reduced and the overall cost of the cartridge per strike is decreased.
In the cartridges disclosed in the aforesaid application, the ribbon is stored on reels. The supply reel stores the ribbon prior to passage past the print point and the takeup reel stores the ribbon after passage from the print point. By driving the take-up reel, some control on the tension of the ribbon may be obtained. In this connection, it will be understood that the tension on the ribbon is important, particularly when flexible leaders are utilized, in order to assure that the ribbon remains taut at the print point while at the same time not creating excessive drag on the ribbon through the leaders.
In a stuffed ribbon cartridge, there may be no reels or at most one reel and control on the tension of the ribbon becomes more problematic. If a drag is placed on the supply of ribbon within the cartridge, that drag is magnified through the length of the leaders and can adversely affect the performance of the cartridge. In this regard, it will be understood that it is important that the ribbon move relatively freely through the long flexible leaders between the storage area and the print point for proper operation of the cartridge and the printer.